The ion $X^{2+}$ is electronically arranged in the same way as the atom Kr. What electronic configuration does an atom of $X$ have?
- A$[\text{Ar}]4s^23d^{10}4p^6$
- B$[\text{Ar}]4s^23d^{10}4p^65s^2$
- C$[\text{Ar}]4s^24d^{10}4p^6$
- D$[\text{Ar}]4s^24d^{10}4p^65s^2$